70 patients with low back pain and a directional preference observed during a mechanical assessment were randomized to treatment using the McKenzie method or motor control exercises. The purpose of this study was to compare the effects that these two treatments had on the recruitment of the transversus abdominis, obliquus internus, and obliquus externus muscles, as well as their effects on pain intensity, functional outcome, and global perceived effect. Outcomes were reported as changes from baseline to 8-week follow-up. No statistically significant differences were observed in the recruitment of the three abdominal muscles, pain, or function between the treatment groups. However, a statistically significant difference was observed for global perceived effect favouring the McKenzie method.